Would be a good size for a pair. When they get to large eventually, it may be a little bit small. I would get 1 male and 3-4 females and keep them all together for as long as you can, I find that is usually the best way to get the pair to have a strong bond and not turn on each other. When they are 5" or so separate all but the pair and hope for the best (or upgrade to a 75 or so and keep them all together)